Dapsyra's Posts
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essegis:From my personal experience running LTO batteries at very low "C" rates, the cycle efficiency is about 99.9%. For comparison, the cycle efficiency of Lead Acid battery is about 70% My bank is 700Ah and the highest instantaneous load it has ever seen is 100Ah. That is 0.14C on a battery that is capable of 10C |
essegis:One man's food is another man's poison. All the "PRO" points I listed cannot be faulted in any objective review. The only complaint I have seen about them that I did not list in my "CONs" list is the claim that their cycle efficiency is lower that other Lithium flavours. My personal experience with LTO is contrary to that claim maybe because I am not running them at 10C. For home solar storage, nobody need 10C. At 10C, the battery bank will be depleted in 6minutes! That will be a very poor design |
NiyiOmoIyunade:Niyi, those PylonTech batteries are quite good. I took a brief look at them back then before settling for the LTO cells. I had a client that ordered large quantity of LTO cells (>120kwh). I seized the opportunity of the bulk purchase to grab some cells for myself at a very affordable price. |
mctfopt:I have the pouch cells. They are 55Ah, 2.4v nominal each. Those cylindrical cells are about 10Ah |
Trippledots:You can say that again. Shipping and Customs duty were responsible for half the cost. The battery bank is located in a very tight area of my power room, so getting good snapshots is very difficult.
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mctfopt:I run 52.8v norminal (2.4v per cell, 22s) |
Trippledots:PROs: At more than 20,000 cycles, the LTO chemistry has the longest life of all the Lithium batteries. It can be discharged to 0v without any serious consequence. Some manufactures actually ship them out at 0v state of charge. Some of mine were at 0v when I received them. LTO does not combust due to overcharge or any other abuse. There are a lot of LTO abuse videos on YouTube. It can be charged and discharged at a very high 'C" rate (10C or higher). You can fully charge a LTO battery in 6minutes if you have a capable charger. I have used mine for over two years now and I have not noticed any loss of capacity. If I consume 300Ah, it will require less than 301Ah to recharge. The cycle efficiency of mine is 99.9%. It does not heat up during charging of discharge. It stays at room temperature 24/7. As at today, LTO is the best battery money can buy. CONs: It is much more expensive than other Lithium brands It is heavy, So, it is not very suitable for mobile application |
adrusa:http://115.28.16.44:81/file/9017.ZIP?spm=a2g0s.imconversation.0.0.4df33e5f8nxeY4&file=9017.ZIP |
ceaser:I was well within the Voc limit of the CC. It was the amps rating that I exceed. I tried to use the Powmr CC to transfer energy from a 60V, 520AH Lithium battery to charge a 24V, 200AH Lithium battery expecting the CC to self limit the charging current to the rated 60A. It didn't. Due to the low internal resistance of both Lithium batteries, the charging current spiked beyond the ability of the CC and out comes the magic smoke. I didn't get to see how high the current went before the smoke but it was less than two minute after I started the process. Mind you, I have always done same with Midnight Classic CCs. |
ceaser:Just don't try it! I have one that I pushed to the maximum power about a year ago. It rewarded me with the proverbial magic smoke. It still power-on but can no longer make power |
spartacus11:Yes, you can connect multiple CC to one battery bank |
ojtech8291:Your CC is probably going into protection mode when the sun is very high due to one or more of the following scenarios. 1. Over Temperature. The temperature of the FETs have gone above the safety threshold due to continuous operation at maximum power 2. Over Current. The output current spiked above the rated capacity for a sustained period 3. Over Voltage. The input voltage rose above the rated MPPT voltage You need to rejig your array to avoid these issues. |
ojtech8291:The SCC of your panel is 9.47A . 3S will produce a theoretical maximum current of about 28.4A. This is still well below the CC rated capacity of 40A. Even if the current attempts to go above 40A, most well built CC will clamp it at the rated value. |
ojtech8291:The only safe option is to use the 100v CC in a 2S3P array as 3S2P arrangement will also exceed the Vmax for the CC ojtech8291:If you use 2S3P format, the array VOC might go above the 70v Vmax the CC can tolerate especially in cool days. This is a sure recipe for disaster. |
earthrealm:It doesn't matter whether it is poly or mono. What matters is the current and voltage ratings. Poly vs. Mono are just manufacturing techniques that don't change the laws of Electricity. The CC don't know and don't care whether it is mono or poly For series connection, match the current but, match the voltage for parallel connections and you are good to go. |
ojeysky:You can put different brands of Solar Panels in series if their current ratings are similar within 5% tolerance You can similarly put different brands in parallel if their voltage ratings are similar or within 5% tolerance |
Thanks mctfopt: |
Where can I get the 24v version you mentioned? mctfopt: |
We currently don't have LifePo4 batteries for sale but we have Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2 or NMC) in 48V, 100AH format with in-built Smart Bluetooth ANT-BMS. Sorry, we don't have stock of ANT BMS for sale. ojeysky:
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Below is the type of report we get from the BMS we bundle with our DIY Lithium batteries. The battery under observation is a 14S 48v 100AH Lithium ion chemistry The BMS is called ANT-BMS, available on Aliexpress. NiyiOmoIyunade:
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Not all Lithium batteries catch fire. Some Lithium chemistries are quite safe even under extreme abuse. I am sure we all have mobile phone with Lithium batteries. How many of such phones have been ignited by the battery? Lithium batteries are quite safe when operated within the specifications given by the manufacturer. For the battery to catch fire, you have to abuse it by operating it outside the limits set by the manufacturer. The gas cooker in your house will catch fire if abused. The generator will also catch fire if abused Your car will catch fire if abused The risk of fire has not stopped us from buying and using the items listed above. We have only learnt to operate them safely. If you do same for Lithium batteries, you have nothing to fear. |
Saipro:I have same version |
The version under reference is running on Windows 10. I also have it running on Android 8 and 9. I did nothing extra, other than just install it to get it working on Android. You can try deleting all it's data, uninstall, reboot and reinstall to see if that will straighten it out Saipro: |
I can feel you Babaegun; I am in the same shoes like you. If not for my large battery bank, I would have ran out of juice today babaegun:
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The cell in question is rated 8AH, 3.2v nominal (3.65v max and 2v min). The 8Ah means that cell will power a 8A load for 1hour. The 200A is the maximum discharge rate which happens to be 25C in this instance. This implies that you can actually put a load of 200A on this 8AH cell. Mind you, there is still only 8AH stored energy in the cell at full charge of 3.65v. Loading the cell at 25C (200A) will fully deplete the cell in 2.4 minutes or less. Yes, you need 40 of the cell to build a 12v 80AH battery bank -4S8P arrangement. earthrealm: |
Lithium batteries do not require an air-conditioned environment especially for Solar Storage. Most Lithium Chemistries can be operated at temperatures between 0-45 deg Celsius without any side effect. They perform better than Pb batteries at high temperatures. They don't require temperature compensation for charging unlike Pb that must be temp compensated when charging at above 25 deg. Celsius. In most EVs, the batteries are water cooled because they get very hot (>70 deg. Celsius) at high discharge rates. Under high acceleration the EV battery can see up to 5C discharge rate. In home Solar storage application, the battery might never go beyond 1C charge/discharge rate. mank1234: |
Niyi, thank you for your usual in-depth analysis. But the matter is not as linear as put. You have to also factor in the round trip efficiency of both chemistries. For every 100AH you take out of lead acid battery you need 130AH to replenish (85% charge and discharge efficiency). Lithium on the contrary has a round trip efficiency of 99.9999% at discharge rates lower than 1C. You take out 100AH, you put back 100AH nothing more. This implies that you will require 30% more PVs, larger CC and bigger cables to charge the same battery if using Pb chemistry instead of Lithium. I have used my LTO batteries for about 15 months without any loss of capacity. Zero degradation. The same mileage goes for the clients we installed them for. I have tons of raw data (5 minutes average sample rate) over the last 15 month which I am willing to share with anyone interested in analysing them. The BattleBorn LifePo4 are unnecessarily expensive for that chemistry. If you are ready to do a little DIY, you can buy the same capacity at about half the BattleBorn price. The most affordable Lithium battery money can buy is the used EV battery. It cost about the same price as the Pb equivalent and will outlast it by a factor of 2 (at least) if handled right. NiyiOmoIyunade: |
Sweet 27.1kWh harvest on 11/3/2019 from 6.3kW "B grade" array. See attached images for detail.
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Are both arrays charging the same battery bank? If not, then the SOC of the batteries at sunrise will definitely affect the performance of the arrays differently. Are the charging profile set identical or optimal on both CC? If those extra 223 days you mentioned were during the months of April to October when solar harvest is at the poorest in Lagos, that must also me factored into the analysis. Can you please help us conduct a scientific analysis of your arrays. The methodology is very simple:- 1. Set identical/optimal charging profile for both arrays on the CC 2. Let both arrays charge the same battery bank 3. Write down the current lifetime harvest on both CCs at sunset as a reference point 4. Every 7days, write down the current lifetime harvest on both CCs at sunset 5. Subtract the values in #3 above from #4. This will give the exact production over the same time frame. 6. Use the data in #5 for your calculations and analysis. I believe this technique will produce results that will be objective and fair on both vendors. Your findings will be an invaluable contribution to this forum. Knowing the type of open minded person you are, I will take the liberty of thanking you for taking up the challenge even before you speak. NiyiOmoIyunade: |
On the surface, it appears as if the Canadian PV is outperforming the Flames PV. But this is not the case. If you do a cost-benefit analysis of both arrays using the real cost per watt of energy produced, you will discover that the Flames panels are outperforming the Canadian panels. A 300w Flames mono PV cost N45k while the Canadian equivalent cost N60k, that is, 33.3% more expensive Now let us do some simple analysis using the instantaneous harvest data supplied (assuming the orientation and inclination are same). 3960w is canadian panels produced 2690w of instantaneous power ==> 67.93% efficiency 3000w of Flames panels produce 2005w of instantaneous power ==> 55.69% efficiency So the Canadian panel is more efficient than the Flames panel by about 12.26% but it is also 33.3% more expensive. To my discerning mind, the Flames PV outperforms the Canadian PV and it gives better value for money than the Canadian PV on this occasion NiyiOmoIyunade: |
See what I found when I opened up my old reliable Mercury 5KVA Inverter for cleaning recently. Mind you, the inverter is located is located in a dedicated power room with a small window not facing the road. Yet, see how dusty it is.
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